1. Make the selected pump type and performance meet the requirements of process parameters such as device flow rate, head, pressure, temperature, cavitation flow rate, and suction stroke.
2. Must meet the requirements of medium characteristics.
For pumps that transport flammable, explosive, toxic, or valuable media, reliable shaft seals or leak free pumps such as magnetic pumps, diaphragm pumps, and shielded pumps are required
For pumps transporting corrosive media, it is required that the convection components use corrosion-resistant materials, such as stainless steel corrosion-resistant pumps and plastic magnetic drive pumps.
For pumps transporting media containing solid particles, it is required that the convection components be made of wear-resistant materials, and if necessary, the shaft seal should be flushed with clean liquid.
3. High mechanical reliability, low noise, and minimal vibration.
4. Economically, the total cost of equipment, operation, maintenance, and management fees should be considered comprehensively, which is quite low.
5. Centrifugal pumps have the characteristics of high speed, small size, light weight, high efficiency, large flow rate, simple structure, no pulsation in infusion, stable performance, easy operation and maintenance.
Therefore, centrifugal pumps should be selected as much as possible, except for the following situations:
a. When there are measurement requirements, choose a metering pump
b. When the head requirement is high and the flow rate is small and there is no suitable small flow high head centrifugal pump to choose from, a reciprocating pump can be used. If the cavitation requirement is not high, a vortex pump can also be used.
c. When the head is low and the flow rate is high, axial flow pumps and mixed flow pumps can be used.
d. When the viscosity of the medium is high (greater than 650~1000m ㎡/s), rotor pumps or reciprocating pumps (gear pumps, screw pumps) can be considered for use
e. When the gas content of the medium is 75%, the flow rate is small, and the viscosity is less than 37.4m ㎡/s, a vortex pump can be used.
f. For situations where frequent start-up or pump filling is inconvenient, pumps with self-priming performance should be selected, such as self-priming centrifugal pumps, self-priming vortex pumps, and pneumatic (electric) diaphragm pumps.
